Heater control valve and heater core bypass

[floridacatfan]

Has anyone actually bypassed the valve and heater core - I’m convinced mine is passing fluid with a vacuum on it and I’m thinking of just going around the entire system and eliminating - was a premolded hose used ?

 

[CDW6212R]

Why do you think the HCV is a problem, is your AC air coming out warm? The blend door is a known problem with all of the 2nd gens, and many other Ford models from the 90's and later on too. I have a problem with two of my 2nd gen's, both have a broken bend door(the top hinge hole breaks off).

 

[410Fortune]

yes
I have bypassed my heater control valve and my heater core in the past
In fact I added the heater control valve to my 1988 bronco II, so that I can easily bypass my heater core in the summer months
I use a zip tie to hold it closed (bypass)
There are at least 3 different styles of heater control valves.

What is the issue you are having?
It is a very simple setup, vacuum applied the flap closes and most of the hot water is fed directly back to the engine

 

[CDW6212R]

I have seen two HCV's that still would flow water with the vacuum applied. One was from my Mountaineer, when I first hunting the warm air AC issue. I replaced the HCV, and then hooked up the old one to the vacuum line; the small valve inside didn't fully shut. So some HCV's work better than others, it might be smart to always test them before installation.

 

[floridacatfan]

My problem is that I know it’s leaking through to the heater hoses and core - I don’t have a blend door issue but the leakage does put heat load into the dash - we use our heaters about 3 days of the year in south Fl and I just do without it with a bypass.

 

[CDW6212R]

Wrapping a zip tie around the HCV is possible on most of them, and that should be enough to keep it closed tight. You could do that once a year as needed.

 

[floridacatfan]

I’m gonna see if a can try the zip tie

 

[410Fortune]

That is how I do it on my Bronco! I have a v8 with headers and a small body drop. My passenger floor used to get hot enough to melt shoes
I finally put in some heat shielding under the carpet and bypassed the heater core (zip tie) to help my poor passengers when we are wheeling in the desert